Processing, which is performed by an air blast device, is widely used as the polishing of workpieces. The air blast device is a device that performs polishing, such as the deburring of surfaces of workpieces, the adjustment of surface roughness, rounding, and the removal of a surface layer, by injecting an abrasive from a nozzle together with compressed air so that the abrasive collides with workpieces.
The size of a workpiece is not particularly limited in the polishing that is performed by a blast device, but a demand for the polishing of small workpieces has increased in recent years. For example, when the workpieces are electronic components, a demand for the polishing of small workpieces has further increased due to the spread of smart phones or tablet terminals.
Since a lot of workpieces can be polished at a time in the polishing performed by an air blast device, the processability of the polishing performed by an air blast device is good. However, since the abrasive is blown to the workpieces together with compressed air as a solid-gas two-phase flow, workpieces having a certain size or weight are scattered. A polishing device and a polishing method, which polish small workpieces, are disclosed in Patent Literature 1. In Patent Literature 1, as illustrated in FIG. 11, auxiliary tumblers into which workpieces are charged are put in a tumbler of a tumbler-type blast device commercially-supplied for general use and blasting is performed during polishing. Accordingly, polishing can be efficiently performed. However, since the auxiliary tumblers are used, the amount of workpieces to be processed is small in regard to the volume of the tumbler. For this reason, a polishing device having higher productivity is required.
Further, there is a case in which workpieces cannot be polished well by a polishing method known in the related art depending on the shape of the workpiece as in cases in which workpieces are very small, are flat, and include grooves. For example, when workpieces including narrow grooves are polished by barrel polishing, polishing media do not easily enter the grooves. For this reason, the workpieces cannot be polished well.